Although over the years the annual number of cases of foodborne salmonellosis within the EU has decreased markedly, in 2014, a total of 88,715 confirmed cases were still reported by 28 EU Member States.

The European Food Safety Authority reported that, after the household environment, the most frequent settings for the transmission of infection were catering services. As evidenced by the reviewed literature, which was published over the last 15 years (2000–2014), the most frequently reported causative agents were Salmonella Enteritidis and Salmonella Typhimurium serovars. These studies on outbreaks indicated the involvement of various facilities, including hospital restaurants, takeaways, ethnic restaurants, hotels, in-flight catering, one fast-food outlet and the restaurant of an amusement park. The most commonly reported sources of infection were eggs and/or egg-containing foods, followed by meat- and vegetable-based preparations.

Epidemiological and microbiological studies allowed common risk factors to be identified, including the occurrence of cross-contamination between heat-treated foods and raw materials or improperly cleaned food-contact surfaces.

Salmonellosis associated with mass catering: a survey of European Union cases over a 15-year period

K. Aleisha Fetters of Yahoo News connected with Schaffner and I on the difference between refrigeration for safety and keeping stuff cool for spoilage and quality reasons.

Here are some excerpts.

Ketchup: Can remain at room temperature.Ever wondered why restaurants keep ketchup on their tables rather than back in the fridge? Because it won’t make you sick, says Benjamin Chapman, PhD, associate professor and food safety extension specialist at North Carolina State University. Ketchup is so acidic that it prevents the growth of harmful bacteria. It will spoil faster if left out on the counter, but it could still take months to turn bad.

Fruits and vegetables: It depends.If you think about it, fruits and vegetables grow outside at temps far higher than room temperature. That’s why, when they are whole, they are safe on your counter. However, when you cut them (or in the case of lettuce, just tear their stems from the ground), you actually rip open the cells of the plant. This releases nutrients, water, and bacteria, and allows them to mingle with each other, says food microbiologist Donald W. Schaffner, PhD, distinguished professor at Rutgers University. For example, when you cut a tomato or avocado, you need to keep it in the fridge to prevent the growth of salmonella. However, it’s worth noting that listeria can grow (albeit slowly) at cold temps. That’s why, even if you keep cut melons in the fridge, you should throw them out or add them to the compost pile after four days, Chapman says.

Mayonnaise: Must be refrigerated.Well, this one is really more of an “it depends,” but we’re going to suggest sticking it in the fridge just in case. Most store-bought mayo is acidic enough to keep on the counter without it growing bad-for-you bacteria all by itself. (That’s why fast-food joints can keep it out in pumps until it’s used up.) But, if you cut some veggies with a knife, and then stick that knife in your jar of mayonnaise, you could potentially introduce bacteria into the mayo that is able to grow at room temperature, Chapman says. Meanwhile, whatever the recipe, homemade mayo is generally not acidic enough to fend off pathogens.

In 2005 I hosted Kitchen Crimes, a television-based series that promoted food safety at home, from dirty sponges to mice poop on countertops, we’ve seen it all. I always inform the public to use a diluted concentration of bleach to water in efforts to wash produce, countertops, and so on without validating the procedure.

From my experience, 100ppm of a diluted bleach solution means absolutely nothing to the home chef and more often than none, an excessive amount of bleach is used.

There are three important factors to consider when looking at food safety at home: hand washing; the use of a digital tip-sensitive thermometer and understanding proper internal temperatures; and, avoid cross-contamination.

Food stored, prepared, cooked and eaten at home contributes to foodborne disease which, globally, presents a significant public health burden. The aim of the study reported here was to investigate, analyse and interpret domestic kitchen practices in order to provide fresh insight about how the domestic setting might influence food safety.

Using current theories of practice meant the research, which drew on qualitative and ethnographic methods, could investigate people and material things in the domestic kitchen setting whilst taking account of people’s actions, values, experiences and beliefs.

Data from 20 UK households revealed the extent to which kitchens are used for a range of non-food related activities and the ways that foodwork extends beyond the boundaries of the kitchen.

The youngest children, the oldest adults and the family pets all had agency in the kitchen, which has implications for preventing foodborne disease. What was observed, filmed and photographed was not a single practice but a series of entangled encounters and actions embedded and repeated, often inconsistently, by the individuals involved.

Households derived logics and principles about foodwork that represented rules of thumb about ‘how things are done’ that included using the senses and experiential knowledge when judging whether food is safe to eat.

Overall, food safety was subsumed within the practice of ‘being’ a household and living everyday life in the kitchen. Current theories of practice are an effective way of understanding foodborne disease and offer a novel approach to exploring food safety in the home.

‘I don’t think I ever had food poisoning’ A practice-based approach to understanding foodborne disease that originates in the home

Science is about disagreements, revising knowledge and generating new evidence-based knowledge (someone will disagree with that).

Don Sapatkin of the Philadelphia Inquirer recently asked a number of food safety types about food safety at home. For fun, I asked friend of the barfblog and known bugcounter, Don Schaffner of Rutgers University (left, prettymuch as shown) his thoughts on the answers.

“Washing a sponge with soap doesn’t get rid of bacteria,” said microbiologist Michael Doyle, director of the University of Georgia’s Center for Food Safety (below, right). They grow at room temperature and get spread around anything else you wipe off. Put the sponge in a microwave for one minute to kill the salmonella and other bacteria,” he said.

Schaffner: Sort of true. Washing a sponge will probably remove some bacteria, but not all. Same with the microwave: it depends upon the microwave, the amount of moisture in the sponge, etc. A better practice may be to put your sponges in the automatic dishwasher, assuming you have one.

Experts say most home kitchens are far dirtier.

Schaffner: Might be true, but science-based head-to-head comparisons are lacking.

Cutting boards should not have hard-to-clean nicks and grooves (wood is better, Doyle said, because the resin has antibacterial properties).

Schaffner: Dean Cliver’s work showed wooden cutting boards to be safer, but the literature is far from clear on the matter.

Washing chicken in the sink may sound hygienic but actually poses all sorts of risks.

Schaffner: Yup, this has good scientific consensus.

“Every time you run your disposal in the sink you are generating a little airflow back up.”

Schaffner: Yup, probably true.

If you do wash chicken in the sink, clean it (the sink) with bleach (1 ounce in 1 gallon of water).

Schaffner: Giving bleach concentration recommendations always concerns me. The units are never the same, the knowledge about the type of bleach is never certain, and the type of surface being cleaned makes a difference (plates versus countertops). I used to dream of creating a webpage that would definitively answer these questions, and do unit conversions. Now I have the same dream except it’s an iPhone app.

Craig Hedberg, a professor at the University of Minnesota School of Public Health (below, left): “If you take this big mass of hot food and put it into a plastic container and put a lid on it, you are holding the heat in and slowing the cooling process, even if you put it in the refrigerator. You want to get it out of bacterial-growth range” – 40 to 140 degrees – “within a couple of hours.” Pouring it into containers no more than four inches deep speeds theprocess.

Schaffner: This is more or less correct, but I believe the correct depth of the food recommendation is 3 inches. It doesn’t really matter how deep the container is, it’s the depth of the food.

If food is not cooled fast enough, spores that survived cooking can germinate and grow bacteria. Reheating leftovers to 165 degrees for 15 seconds will kill them.

Schaffner: This is the general time temperature recommendation. I’ve never checked to see what log reduction it would give for Clostridium perfringens cells, but it’s likely sufficient.

Hedberg advises against washing prewashed bagged lettuce; E. coli and salmonella can adhere to cut surfaces and tiny pores. “If it’s contaminated, your washing it again would not eliminate the contamination,” he said. “If it is not contaminated, your washing may contaminate it.”

Schaffner: That is consistent with expert recommendations.

Hands should be washed vigorously with soap before preparing food or eating; after handling raw meat, poultry, fish, or even raw produce; and after smoking, eating, or drinking.

Schaffner: Also after pooping or changing a diaper, handling pets etc.

Countertops, cutting boards, utensils, etc., should be cleaned with hot water after every use.

Schaffner: I also recommend soap.

Cooking and holding temperatures should be checked, which means having working thermometers. (The fridge should be set between 32 and 40 degrees Fahrenheit; the freezer, at zero or below).

Schaffner: They nailed this one.

Everything should be clean: Garbage covered, or at least three feet from food-preparation areas; pets never allowed in the kitchen (and hands washed after petting).

Schaffner: I’m not sure where the three-foot recommendation comes from, and it’s probably not science-based. Does anyone really exclude their pets from the kitchen? When we had dogs their food and water dishes were in the kitchen. Good luck getting a cat to do anything you want to do.

To bring home cooks up to speed, the Rutgers University Cooperative Extension posts a quick home kitchen food safety best practices check-Up list: http://bit.ly/1xDO19F.

Gingerbread wriggling with maggots, a sausage roll growing fuzz on it, a salmonella outbreak and the sale of four-year-old frozen oysters were among bought food complaints the Ministry of Primary Industries dealt with from Whangarei in the past three years.

Of a dozen complaints in that period, there were four last year and only one this year.

Foodservice professionals, politicians, and the media are often cited making claims as to which locations most often expose consumers to foodborne pathogens. Many times, it is implied that most foodborne illnesses originate from food consumed where dishes are prepared to order, such as restaurants or in private homes. The manner in which the question is posed and answered frequently reveals a speculative bias that either favors homemade or foodservice meals as the most common source of foodborne pathogens. Many answers have little or no scientific grounding, while others use data compiled by passive surveillance systems. Current surveillance systems focus on the place where food is consumed rather than the point where food is contaminated. Rather than focusing on the location of consumption—and blaming consumers and others—analysis of the steps leading to foodborne illness should center on the causes of contamination in a complex farm-to-fork food safety system.

Foodservice professionals, politicians, and the media are often cited making claims as to which locations most often expose consumers to foodborne pathogens. Many times, it is implied that most foodborne illnesses originate from food consumed where dishes are prepared to order, such as restaurants or in private homes. The manner in which the question is posed and answered frequently reveals a speculative bias that either favors homemade or foodservice meals as the most common source of foodborne pathogens. Many answers have little or no scientific grounding, while others use data compiled by passive surveillance systems. Current surveillance systems focus on the place where food is consumed rather than the point where food is contaminated. Rather than focusing on the location of consumption—and blaming consumers and others—analysis of the steps leading to foodborne illness should center on the causes of contamination in a complex farm-to-fork food safety system.

Follow-up surveys were done six months later and found that individuals who had not had food poisoning increased their optimism: it’s risk perception 101; things didn’t go bad yesterday so there’s a better chance things won’t go bad today.

And, as usual, there was a call for more effective food safety communication. No tips on how to do that.

Abstract

Whilst the scale of food poisoning in the home is not fully understood, the increase in sporadic cases of Campylobacter continues to place focus on home hygiene and domestic food safety practices. Domestic hygiene has rarely been identified as a risk factor for the incidence of campylobacteriosis but due to the high levels of sporadic cases of Campylobacter, cross contamination from kitchen practices remains of significant interest. Due to the complexities of human nature, finding the true risk perceptions and practices that take place in the kitchen is challenging, with social desirability bias affecting the results of surveys and optimistic bias influencing risk perceptions. This study looks at self-reported kitchen behaviours and perceptions of people who have had campylobacteriosis in comparison to people who have not had food poisoning. It also investigates microbiological kitchen hygiene within a smaller sample. The survey crucially includes a longitudinal element to investigate any change that may take place after a period of six months has elapsed. Optimistic bias was evident in both groups and no significant difference in perception was noted in the baseline study. However, the longitudinal study showed that individuals who had not had food poisoning increased their optimism, introducing a significant difference in optimistic bias between the two groups after six months had elapsed. Self-reported kitchen behaviours also exhibited a difference between the two groups, with the individuals who had campylobacteriosis responding more favourably with the exception of washing chicken and washing salad leaves sold in a bag. No evidence of kitchen hygiene differences could be found between the people who had suffered campylobacteriosis in comparison to people who had not had food poisoning. The results of the survey demonstrate that more effective food safety communication is required. Important messages such as ‘not washing chicken’ seem not to have been absorbed and the good practices become routine. These messages need particularly to be aimed towards people who may not perceive themselves as being at risk of getting food poisoning, such as the young, although the challenge of changing the practice of those who perceive themselves to be at low risk remains.

Friend of the barfblog Don Schaffner wrote that in response to a dumb statement by the credibility-questioned American Council on Science and Health with the headline, “Avoiding food poisoning starts in your own kitchen.”

In response to an ill-informed Jane Brody column in the N.Y. Times, ACSH’s Ariel Savransky says, “Jane Brody goes into a lot of detail about steps that can be taken to prevent illness from foods you prepare. It may seem like an overdose of minutiae to bear in mind, but the steps are really not so hard to implement and the fact that 70 percent of food poisoning is caused by unsanitary kitchen practices really makes it necessary to follow the advice she provides, and which we here at ACSH endorse.”

Where’s the fact?

We took a shot at the question, and we publish in peer-reviewed journals. Go evidence, or go home.

Food service professionals, politicians, and the media are often cited making claims as to which locations most often expose consumers to foodborne pathogens. Many times, it is implied that most foodborne illnesses originate from food consumed where dishes are prepared to order, such as restaurants or in private homes. The manner in which the question is posed and answered frequently reveals a speculative bias that either favors homemade or foodservice meals as the most common source of foodborne pathogens. Many answers have little or no scientific grounding, while others use data compiled by passive surveillance systems. Current surveillance systems focus on the place where food is consumed rather than the point where food is contaminated. Rather than focusing on the location of consumption—and blaming consumers and others—analysis of the steps leading to foodborne illness should center on the causes of contamination in a complex farm-to-fork food safety system.